1. Field of the Invention
This invention relates in general to exhaust system combustors of the type used to regenerate particle traps for catching particulate matter in the exhaust system of a vehicle or the like. More particularly, but without limitation, the present invention relates to such combustors which have a compact design.
2. Description of the Prior Art
Some exhaust systems for vehicles or the like include a particle trap for reducing particulate emissions and other emissions. Traps of this type are especially useful on the exhaust systems connected to diesel engines. Over time such particle traps become saturated or clogged and require regeneration. This regeneration can be achieved by a combustor connected to heat the trapped material to a combustion temperature and thereby clean the trap.
Some combustors for exhaust systems are housed aside from or separate from the exhaust conduit. In other systems the combustor extends entirely within or partially within the exhaust conduit. In order to achieve a compact design it is desirable to have the combustor entirely within the exhaust conduit. In this system a combustion chamber resides in the exhaust conduit and exhaust gases flow around and into the combustion chamber on a path to the particle trap. In such a system it is difficult to arrange the ducts for conveying combustion air to the combustion chamber and the fuel conduit for conveying fuel to the combustion chamber. More particularly, it is a problem to connect the systems in a way which does not degrade the atomization of the fuel in the combustion chamber.
For example, it is particularly a problem to connect the fuel conduit to the combustion chamber which resides within the exhaust conduit because the heat of the exhaust gases passing through the exhaust conduit can overheat the fuel in the exhaust conduit causing undesirable variations in the fuel temperature and pressure. In addition, expansion and contraction of the air duct and fuel connections to the atomization portion of the combustion chamber can cause misalignment of the atomization components of the combustor which degrades the atomization and reduces the efficiency of combustion.
It is accordingly an object of the present invention to provide an improved combustor of a compact design which has a combustion chamber entirely within the exhaust conduit. It is also an object of the present invention to provide such a combustor having a tolerance to thermal gradients and effects created in the combustor by exhaust gases passing through the exhaust conduit.
It is also an object of the present invention to provide an improved combustor for use in an exhaust gas system which has a fuel conduit which is less exposed to heating from the exhaust gases in the exhaust duct while also providing such a fuel conduit which is compliant to prevent misalignment of the atomizer to which the fuel conduit is connected.